Transcript Lecture 4 - Empyrean Quest Publishers

Today!
From Earth’s Perspective:
Celestial Motion:
Stellar Motion
Solar Motion
Planetary Motion
Some stars and constellations
Are circumpolar—never rise or set.
Constellation vs Asterism!
A constellation is one of
88 listed ‘states’ or regions
in the sky: like Orion.
An asterism is not on the list
Of 88, but forms a shape
In the sky: like the Big Dipper,
Part of the constellation Ursa
Major.
Finding Planets:
Once you find the North Star,
Turn around 180 degrees—
The Ecliptic and the planets
will be in the sky toward the South.
Circumpolar Constellations at our Latitude.
The stars (at a given time of night) shift 1 degree a day
Because the earth is orbiting the sun.
Thus the sidereal day is 23 hours and 56 minutes:
It is the time for a star to return to the same place
In the sky.
seasons caused by tilt of earth’s axis,
solstices--maximum and minimum light,
equinoxes equal light on northern and southern hemisphere.
Solar motion:
Mean solar day--24 hours by definition.
Average return of sun to same angle relative to the horizon.
NOTES: Planetary motion:
retrograde motion--apparent backtracking of
planets in sky from earth's perspective.
inner planets--Me and Ve
--stay within 'maximum elongation'.
conjunction vs opposition
Mars going RETROGRADE: journeying backward against constellations.
Venus: always within 46 degrees of the sun—
its MAXIMUM ELONGATION
(Mercury within 26 degrees)
Mercury 8/30/02
Above Cloud Center
w/ Venus Upper Left
Note conjunction and opposition as seen from the Earth.